Apparatus for forming side openings in metal tubing



Feb. 2, 1943. J HOLMES ET AL 2,310,083

APPARATUS FOR FORMING SIDE OPENINGS IN METAL TUBING Filed May 28 1941 8Sheets-Sheet l Jay? Jay 6- 1 INVENTORS 0'41 QIVa-Avw M ts} 25 ATTORN YAFeb. '2, 1943. J. Q; HOLMES EIAL 2,310,083 APPARATUS FOR FORMING SIDEOPENINGS IN METAL TUBING Filed May 28, 1941 8 Sheets-Sheet 2 1 VENTOR- mA TTORNEXa Feb. 2, 1943. J. Q. HOLMES ETAL 2,310,083

APPARATUS FOR FORMING SIDE OPENINGS IN METAL TUBING 8 Sheets-Sheet 5lNVENTgR s ATTORNEYA- Feb. 2, 1943. J. Q..HOI;MES EI'AL APPARATUS FORFORMING SIDE OPENINGS IN METAL TUBING 8 Sheets-Sheet 4 Filed May 28,1941 INVENTORS $4.. A TTORNE Y:

Feb. 2, 1943. H L S HAL 2,310,083

APPARATUS FOR FORMING SIDE OPENINGS IN METAL TUBING Filed May 28, 1941 8Sheets-Sheet 5 M M g. Z5 ATToRwEtrf F ,19 3 J. Q. HOLMES Em. 2,310,083

APPARATUS FOR FORMING SIDE OPENINGS IN METAL; TUBING f4 INVENTOR-ATTORNEY4 ,1 J. Q. HOLMES ETAL 2,310,083

APPARATUS FOR FORMINGSIDE OPENINGS IN METAL TUBING Filed May 28, 1941 8Sheeds-Sheec 7 WIAVAVA Isl lo HZ V36 INVENTOR 5 ATTORN EYA- Feb 2, 1943-J. Q. HOLMES ETAL 2,310,083

APPARATUS FOR FORMING SIDE OPENINGS IN METAL TUBING 7 Filed may 28, 19418 sheets-sheet a I] r LI ATTORNEW Patented Feb. 2, 1943 umrso "sr 'r-ssPATENT- .os-Fic's mam em 'smmss Jog-p.00; Holmes anl'Oasl J. Wiegand,Anderson.

was, men.

to General Motors Corporation, a mention of Delaware 1 Application Kay26, 1641, Serial No. 896,656

C CIIIII. (CL 153-2) This invention relates to the fabrication of srti-'clss made of metal tubing, for example, the oil distributing manifoldfor the crank shaft bearings. of an internal combustion engine.

The copending application of Charles A. Nichols and George L. weiser.Serial No. 385,618, illed March 27, 1941, discloses a method ofmanufacturing a T from metal tubing. The first step of the method is tosqueeze a portion of' one of the tubes between dies which are so shapedthat a portion of the side wall of the tube is pinched or creased toprovide a portion which has an exterior surface which is sphericallyconvex. The next step is to force a punch through the spherically convexportion of the tubing while the tubing remains confined between theshaping blocks. The punch is made of hardened metal andis carefullypolished and chrome-plated. Its tapered lower end enters the sphericalsurface and punches out a hole. While the tubing is confined between theforming blocks this spherical surface is maintained so rigid as towithstand the punching without pushing the metal of the sphericalportion inwardly. When a hole is started in this spherical portion thetapered part of the punch flares the hole in such'fashion as to form anannular flange extending outwardly, thus defining a socket for thereception of another piece of tubing.

The present invention has for its object the provision of a machine bywhich the method disclosed in the Nichols and Weiser application may bepracticed with great facility. More particularly it is an object oftheinvention to provide a machine for forming a plurality of side open:

ings in a length of tube.

A further object of the invention is to provide means for closing one orboth ends of the tube concurrentlywith the formation of the side openings.

A further object of the invention is to provide for automaticallyfeeding lengths of tubing from a magazine'to the forming dies and forautomatically ejecting the tubing after it has been operated upon.

Further objects" and advantages of the present invention will beapparent from the following description, reference being had to theaccompanying drawings wherein a preferred embodiment of the invention isclearly shown.

- Inthe drawings:

Fig. '11s a side elevation of oneof the tube forming die blocks'shown inFig. 2. Fig. 1 is a view in the direction of arrow i of Fig. 2.

blocks when separated and before enga ing a tube. Fig. 2 is asectional-view'on the line 2-2 of Fig. i; Fig. 2 includes also afragmentary side view of the piercing punch.

Fig. 3 is a view similar to Fig. 2 showing the shaping of the tube bythe forming die blocks. 'Fig. 3 is a sectional viewon the line 2--2 ofFig. 1.

Fig. 4 is a cross sectional view taken on the line 4-4 of Fig. 1 showingthe formation of the tub n adjacent to and on both sides of thespherical convex portion of the tube as shown in Fig. 3.

Fig. 5 is a view similar to Fig. 3 showing the piercing and flangeflaring .punch in downward position. V Y

8. 6 is a sectional view on the line 6-6 of Fig. 7 showing the piece oftubing shown in Fig. 5 assembled with another piece of tubing extendingat right angles to the first piece.

of Figs. 8 and 8a. 7

view on the line li-IU in the direction of arrow 1 Fig. 10 is asectional of Fig. 8. V

Fig. 11 is a sectional viewyon line ll-Il of Fig. 10.

Fig. 12 is a sectional view on line 12-" of Fig. 8-with the upper memberin lower position.

Fig. 13 is a view similar to Fig. 12 with the upper member in upperposition.

Fig. 14 is a sectional view on line "-44 of Fig. 8 and shows-the uppermember in lower ,po-. sition.

Fig. 16 is a view similar to Fig. 14 with the upper member 'in upperposition.

Fig. 16 is a sectional view on line i6|6 of' Fig. 8 with the uppermember in lower position. Fig. 17 is a view similar to Fig. 16 showingthe upper member in upper position.

Fig. 18 is a sectional view on line il-ll of Fig. 8 showing the uppermember in lower position. Fig. 19 is a'view similar to Fig. 18 showingthe upper member in upper position.

Referring to Fig. 2, thetube '1' is located between die blocks 26 and 2!providing semi-cylin- Fig. 2 is a cross sectional view of the two dietsdrical surfaces 22 and 28 having radii equal to the radii of the outsidesurface ofthe tube T as indicated by the arrows 24 and 23. The surfaces22 and 23 merge into cylindrical surfaces 26 and 21 having radiirepresented by the arrows 28 and 29 which are less than the radii 24 and23. The surface of block 23 (Fig. 1) having the radius 23 as indicatedby numeral 33 in Fig. 1.. Just above the surface 33 there is a shallowgroove 3| interrupted by a semi-cylindrical groove 32. Groove 32 extendsto a step 33 which steps oil to a semi-cylindrical groove 34 of greaterradius than groove 32. The block 2| is provided with similar surfaces32. 33 and 34. Block 23 includes parts 23a engaging grooves 2|a of part2|.

When the dies 23 and 2| are separated as shown in Fig. 2. a section oftubing T is placed upon the parts 23a. Then the dies 23 and 2| are movedtogether to cause the tube to take the form shown in Fig. 3. Theportions 26 and 21 of the dies 23 and 2| deform the tube T and cause aspherically convex portion Ts to be formed. This portion in effect risesup like a blister within the space defined by the two cylindricalgrooves 32. The portions of the tube immediately adjacent to and ondiametrically opposite sides of the portion Ts are formed as shown inFig. 4 by the surface defining the grooves 3|. These pinched portions ofthe tube T are marked TD.

While the tube T is thus confine-:1 between the dies 23 and 2 I, thesecond operation is performed. This comprises forcing the punch 43downwardly through the opening defined by the cylindrical grooves 34 and32. Punch 43 has a lower end portion 4| for piercing a hole in theblisterlike spherical part Ts and a'tapered portion 42 for spreading themetal surrounding the hole formed by portion 4| and for causing thespread metal to form an upwardly extending annular flange T! shown inFig. 5, said flange being trued by portion 43 of punch 43.

The operating surface of punch 43 should be carefully polished andchrome-plated in order to secure best results.

Following the operations performed by the dies 23 and 2| and the punch43, the tube T is ready to receive a branch connection t of suchdiameter as to be snugly received within the socket provided by theannular flange T1. The tube section t has an annular flange t forengaging the outer edge surface of the flange Tf. After the assemblyshown in Fig. 6 has been made, the portions T2) of tube T are deformedso as to squeeze the flange TI more firmly around the tube t. Theapparatus for performing the operation shown in Fig. 7 isdisclosed inSerial No. 385,518.

The apparatus which forms the subject matter of the present applicationprovides a length of tubing with a plurality of side openings, eachopening being formed according to the method disclosed in Figs. 2, 3, 4and 5. The dies 23 and 2| which are used with the apparatus are the sameas the dies shown in Figs. 1 to 5, excepting that the parts 230 and 2|aare omitted. Parts 23a are replaced by retractable pins 3| shown in Fig.15.

Referring to Figs. 12 and 13, it will be seen that the machine comprisesa lower assembly and an upper assembly. The lower assembly includes abase 33 adapted to be mounted upon the bed of a punch press. Base 53supports a stationary bar 3| and a movable bar 32 grooved at 3|a and32a, respectively, to receive a length of tubing T in Fig. 2. Bar 3|carries a plurality of spaced dies 2| cooperating with the dies 23carried by the bar 32 (P18. 10). The bar 32 is movable .73

horizontally relative to bar 3| by a cam operated toggle mechanism whichwill now be described with reference to Fig. 10 and Fig. 8.

Bar 32 is recessed to receive a plurality of blocks 33 attached byscrews 34. Each'block 33 is provided with two spaced ears 33 supportinga pin 33 passing through a toggle link 31 and the left and (Fig. 10) ofwhich is formed cylindrically and is received by a cylindrical bearing33 in block 33. Link 31 is connected by pin 33 with link plates 33connected by pin 3| with a stationary toggle block 32 attached by screws33 to base- 33. The pressure which is exerted against the block 62horizontally and to the right in Fig. 10 is transmitted to the base 33principally through a wedge block 64 having an inclined surface bearingagainst a similar surface of the block 32 and having a vertical surfacebeaning against the surface 63 of base 33. Screws 63 secure the wedgeblock 64 to the base 33 and wedge this block between surface 63 of base33 and the toggle block 62. The right hand end of link 31 (Fig. 10) andthe left hand end of block 62 are formed cylindrically and are receivedby cylindrical bearings in a toggle link block which is located betweenthe link plates 60. A pin 63 passes through the block 61 and through thelink plates 33 as shown in Fig. 11. The proiecting ends of the pin 61carry rollers 39 received by cam slots I3 in cam plates II which areattached by screws 12 to an upper block 13 adapted to be secured to theram of a punch press. This block 13 and the parts carried therebyconstitute the upper assembly of the apparatus. As shown in Fig. 80.there are six cam plates H which operate in three pairs. Each pair ofplates II is associated with a. toggle mechanism such as shown in Figs.10 and 11. Each plate 1| passes through an opening 14 in base 33 and issupported laterally on one side by the toggle mechanism and on the otherside by a plate I3 secured to base 33 by screws 13. when the block 13 isin its lower-most position shown in Fig. 10. the cam 1| will be locatedso that the toggle pins 36, 39 and 6| will be in horizontal alignment,thereby causing the bar 32 carrying the dies 23 to be located as shownin Fig. 10 but closest to the dies 2| to perform the operation shown inFigs. 3 and 4. When the block 13 is in the uppermost position as shownin Fig. 13 the toggle pin 59 will be elevated above the pins 38 and 3|,thereby causing the bar 3| to be moved toward the right so as toseparate all of the dies 23 from the dies 2 I.

Downward movement of the block 13 causes each of a plurality of punches43 to be moved from the position shown in Fig. 3 to that shown in Figs.5 and 10 in order to perform the operations of piercing the sphericallyconvex portion Ts of Fig. 3 to form a side opening surrounded by flangeT! as shown in Fig. 5. The cam slots 13 are so shaped that the sphericalportion Ts of Fig. 3 will be formed in advance of contact thereof by thelower end of punch 43. Each punch 43 is received by a vertical hole in abar 33 secured by screws 3| to plate 13. As shown in Fig. 841 there aretwo bars 33 each carrying three punches 43. Each punch 43 is maintainedin its socket provided by bar 33 by a ball 32 urged by spring 33 into agroove 34 provided in the punch. The pressure exerted by the ball 32 issufiicient to retain the punch 43: but the punch 43 may be easilyremoved from its supporting bar 33 by downwardly on the cam plate I"therethrough.

punch 40 when the plate I3 is in uppermost sitionr Each \bar so islocated with respect to the plate I3 by a dowel washer 34, the innercylindrical bore of which is aligned with a bore 30 in plate I3 in abore 34 in bar 30. The bores BI and" together with the uniting bore ofthe washer 34 provides for the guidance of a flange 31 integral with atube 89 receiving a spring 89.

The tube 30 is integral with a pressure pad 90 which is urged by thespring 99 against the tube T which is located in the grooves 5la and 32aof the bars ii and 02 respectively, when the plate I3 is in lowermostposition. when the plate 03 is moved upwardly the lower end of thepressure pad 90 will be elevated above the tubing receiving grooves BIaand 02a by virtue of the engagement of the flange 31 with the shoulder88s at the lower end of the bore 80 of bar as shown in Figs. 9 and 15. a

After the operation shown in Figs. 3, 4 and have been performed upon thetubing and it is elected from the dies 20 and 2| and the bars 02 and IIdue to the relative movement between the bars BI and 52 and a plurality.of elector pins" and 92 (Figs. 12 and 13). The bar 52 moves relative tothe'pins 92 as shown when comparing Figs. 12 and 13. Pins 92 arestationary and are secured by screws 93 to a bar 94 carried by base 60.When the bar 52 moves to the right from the position shown ,in Fig. 12to that shown in Fig. 13, the ends of rods 92 pro ject into the grooves02a. During movement of bar 02 toward the right, rods9| move from theposition shown in Fig. 12 to that shown in Fig. 13 so that their endsproject into the grooves tin of bar BI. To accomplish this the pins 9iare attached by screws 35 to a bar 96 connected at its ends with theends of bar 52 by straps 91 (Fig. 12) attached by screws 38 and dowels99 (Fig. 8).

Referring to Figs. 8, 14 andit will be seen that the lengths of tubing Tto be operated upon are stacked in a magazine comprising two chutes I90each providing a downwardly inclined channel for receiving end portionsof the tubes T.- This channel bends near the lower end of the chute intoa vertical portion having an outlet I M formed in one of the flanges ofthe chute. The movement of the lowermost tube T through the outlet IN isresisted by pawls I02, each of which engages a tube near one endthereof. Each pawl I02 is pivoted at I03 upon a pin I04 (Fig. 8)extending from the chute; and a coil spring I05 surrounding the pinurges the pawl I 02 in a clockwise direction in Figs. 14 and 15. In Fig.8 the lowermost tube T is indicated in dot-dash lines. Each chute I00 issupported by a bracket I06 and a block I01 attached by screws I08 to theflange I09 of a plate IIO located over the bar 96 which carries theejector pins 3|. For the sake of clearness this plate H0 is not shownin'Fig. 8.

The lowermost tube T is withdrawn from the magazine by two fingers III(Figs. .14 and 15) each connected by pin II2 with-a slide bar H3carrying a pin II4 providing a bearing for a roller II5 cooperating witha cam slot H6 in a cam plate III attached to plate I3. Bar II3 slidesbetween the adjacent edges of the block 15 which guide the cam II (Fig.8). The bar H3 is confined between the base 50 and a plate II8. securedto the base by screws 9. Plate Ill provides an opening for the passageof the Plate III is recessed to receive a spring I 20 urging a pressurepad I2I against the upper surface of the bar III. Each finger IIIis'biased downwardly by leaf-spring I22 having its fixed end confinedbetween bar H3 and a plate I23 secured to bar III by screw I24.

During movement of plate 13 downwardly into a position shown in Fig. 14the cam plate I" causes the bar II3 to move toward the left in orderthat the fingers I Il may hook themselves over the lowermost tubing Tthen in' the magazine as shown in Fig. 14. The movement of the fingersII I into the position shown in Fig. 14 takes place concurrently withmovement of the die 20 toward the die 2| in order to form the tube Tthen between these dies. During upward movement of plate I3 these diesare separated as shown in Fig. 15 and the ejector pins 9I and 32 causethe tubing T which has just been op erated upon to be removed from thedies in the die plates 5i and 52 and to descend through an opening I30into a suitable hopper. During the upward movement of plate I3 for thepurpose of opening the dies and efi'ecting the election of the work. thetube T, which in Fig. 14 was the lowermost one in the magazine, has beenmoved by the hook fingers III into the position shown in Fig. 15 fromwhich position it may gravitate between the dies 20 and 2i. In orderthat this tube T will not then descend through the opening I30, two stoppins I3I are released and are caused by spring action to niove acrossthe opening I30 to block the descent of the tube which has just beenmoved by the fingers I II into the position shown in Fig. 15. The stoppins I3I are so controlled that they are maintained in a retractedposition during upward movement of the plates I3 for a time sufilcientto permit'gravitation from the dies of the length of tubing T which hasbeen operated upon. However, before the fingers III have arrived at theposition as shown in Fig. 15, the fingers I3I have been released so thatthey become operative to prevent the tubing T, which has just beenretracted by the fingers III from descending below the dies 20 and 2|.

The mechanism for controlling the stop pins I3I will now be describedwith reference to Figs.

16 and 17. Each finger I3I is horizontally slidable in die block 52which is provided with a bore I32 for receiving the tubular head I33 oithe pin I3I. Head I33 is provided with a longitudinal groove I34 forreceiving one or the other of two pins I35 mounted in the block 02 andextending into the bore I32. The pin IN is urged toward the left by aspring I36 confined within the bore in the head I33 and in a bore I31 ofa block I38 secured by screws I39 to bar 52. When the die bar 52 hasmoved into contact with the bar 5| as shown in Fig. 16, the pin I3!occupies a position relative to the bar '52 such that its head I33 iscaught by the lower end of a latch pin I40 provided with a head HI andwith a notch I42 for receiving a leaf spring I43 biased to urge the p nI40 downwardly into the position shown in Fig. 16. Spring I43 isconfined between the bar 52 and the block I38 on its lower side and aplate I44 on its upper side. Plate I44 is secured together with thespring I43 by a screw I45 to the block I33.

- Inorder that each pin I3I may be released at a t me preceding thearrival of a tube T withdies, each of the latch pins I must be ele- 4vated. Upward movement of pins I from the position shown in Fig. 16tothat shown In Fig. 11 is effected by a lifter I50 of generally tubularformation and provided with a flange III which I53 aligns with a boreI51 in the plate 13. These aligned bores provide a cylindrical guide forthe annular flange I50 extending from the tube I504 The portion of thetube I50 below the flange I50 is guided by a bore I58 of the bushingI53, said, bore being of smaller diameter than the bore I50. Rotationofthe tube I50 is prevented by a key I attached to the bushing I53 andreceived by longitudinal groove IOI in the lifter tube I50.

A spring I52 within the tube and the bores I55 and I51 urges the tubeI50 downwardly until. its flange I58 is caught by a shoulder I03 Joiningthe bore I50 of smaller diameter with the bore I 55 of larger diameter.

when the plate 13 is in its lowermost position, the lifter tube I50 isalmost completely telescoped within the bushing I53 and the plate I3,-and the spring I52 is fully compressed. As the plate 13 ascends, thespring I52 is permitted to expand so that the lower flange I5I of thelifter I50 will remain yieldingly pressed against the plate I44. As theplate 13 moves upwardly the die bar 52 moves toward the right from theposition shown in Fig. 16, but the pin I40 remains for a time inlatching position so that the pins I 3I cannot be released so as toextend to the left of the bar 52. During movement of the bar 52 towardthe right, the heads I of the pins I40 are received by the notches I52of the lifters I50. The cams H are so shaped that, before the plate 13has reached its uppermost position. the die bar 52 will have been fullyretracted and the tubing T operated upon ejected from the die andpermitted to gravitate through the passage I30. During the latterportion of the ascent of the plate 13 the upper flanges I50 of thelifters I50 will be engaged by the shoulders I03 of the bushings 53 andthereafter the pins I40 will be elevated into the position shown in Fig.17, thereby releasing the pins I3I so as to permit these springs I36 tocause the pins to extend across the passage I30 just below the dieopenings and the grooves Ma and 52a of the die bars 5I and 52. Therelease of the pins I3I and their movement into this position will takeplace before the roller II 5 has been engaged by a cam lobe I liedefining a part of the cam slot II5. After the pins I3I have beenprojected across the opening I30, the lobe IIGa engages the roller H5and causes an abrupt acceleration in the movement of the notched fingersIII to take place toward the right, thereby giving the tubing then beingwithdrawn from the magazine a quick snappy movement which is abruptlystopped, thereby causing.

the tubing more readily to leave the notch provided by the fingers IIIand to descend into the space between the dies 20 and 2 I.

tact with the bar 01 the pin m remains stationary so that relativemovement between the pin I and the head I33 of pin I3I takes place.

,By the time the bar 52 has been placed in contact with the bar 5I (Fig.16) the lower projecting end of pin I will have arrived at the left ofthe head I33 of pin I3I, thereby permitting the spring I43 to move thepin I 40 downwardly into its latching position.

The lengths of tubing T are longer than the die bars 52 so that endsthereof project as indicated by dot-dash lines Te in Fig. 9. These endportions may be squeezed or crimped together in order to close the endsof the tube. This operation is performed at each end by the closing ofjaws I10 pivoted on a rod "I and carrying pins I12, supporting rollersI13 cooperating with cam surfaces I14 and "5 (Fig. 13) formed in a rodI10 attached to the plate 13. The rollers "3 are urged against the rodI10 by plungerg I11 sliding in bores I10 provided by brackets I10 whichtogether with the plungers house springs I00 for urging the plungersinwardly toward the rod I10. The cams I14 and I15 are so shaped thatwhen the rod I15 is in the uppermost position the jaws I10 will beopened, but will be closed as shown in Fig. 8 when the rods I15 are inlowermost position as shown in Fig. 9.

As the tubes T descend through the chutes I00 they are so guided thattheir ends project sub- Te of tube T. Adjacent the right end Te of tubeT, there is located a bracket 205 notched at 200 to receive a lever 201pivoted on a pin 200 and urged by a spring 209 clockwise. The arm 2" oflever 201 constitutes a right hand guide for engaging the end Te oftube'I'. Spring 200 has sufliclent force to move the tube T endwise toengage the left hand. guide 203, in case tube T does not already engageit on being forced downwardly by pressure pads 00. Therefore by the timethe jaws I10 start to crimp the ends of the tube, the tube will stillremain in position so that the end portions which project beyond theends of the bars 5I and 52 will remain substantially equal. Thereforethe end portion of the tube to be crimped by the jaws I10 will besubstantially equal in extent.

As shown at the left hand end of Fig. 9, each rod I10 is provided with ashank I00 received by bore in plate 13 and provided with a key slot "Ireceived by a key I02 which prevents rotation of the rod I10. Rod I15 isprovided with an an- 2181,11?! gggove I03 lriceitl ing arcuate flangesI04 of w er mem rs 05 attach toplate ed by screws I00 The upper plate 13is provided with pilot bushings I30 each for receiving a pilot rod "Iextending from the base 50 (Figs. 8, 8a and 17).

While the embodiments of the present inven- During the followingdownward movement of tion as herein disclosed constitute preferred theplate 13 the lower end of the lifter I50 will be yieldingly pressedagainst the plate I40, thereby permitting the spring I43 to urge thelatch pin I4I downwardly against the head I33 of pin I3I. Duringmovement of the bar 52 into 0011- forms, it is to be understood thatother forms might be adopted, all coming within the scope of the claimswhich follow.

What is claimed is as follows:

1. Apparatus for forming a side opening in a length of metal tubingcomprising a pair of relatively movable dies for clamping the tubing andfor forming a bulge in a side wall of the tubing, a punch for piercingthe bulged portion of the tubing, a reciprocatory member for moving thepunch at right angles to the axis. of the tubing, and a mechanismoperated by the reciprocatory member for effecting relative movementbetween the dies in a direction at right angles to the axis of thetubing and to the direction of movement of the punch said mechanismmaintaining the dies clamped against the tubing while the punch piercesthe bulged portion.

2. Apparatus according to claim 1 in which the mechanism for effectingrelative movement between the dies includes a cam carried by thereciprocatory member and a toggl mechanism connected with one of thedies.

3. Apparatus according to claim 1 further characterized as having amagazine for holding a quantity of lengths of tubing, and a mechanismfor withdrawing a tube from the magazine and causing it to be placedbetween the dies.

4. Apparatus according to claim 1 further characterized as having amechanism for pinching together an end portion of the tubing, saidmechanism including a cam carried by the reciprocatory member and a pairof jaws for engaging the tubing and providing follower elements engagingthe cam.

5. Apparatus for forming a side opening in a length of metal tubingcomprising dies for clamping the tubing in a horizontal position and forforming a bulge at the upper side of the tubing, one of the dies beingfixed and the other mounted for horizontal movement toward the fixeddie, a vertically movable punch for piercing the bulged portion, avertically movable reciprocatory member for supporting the punch, amechanism operatedby the reciprocatory member for effecting horizontalmovement of the movable die, and

mechanism advancing the movable die against the tubing and the tubingagainst the fixed die during downward movement of the punch and ahead ofengagement of the punch with the tubing, said mechanism retracting themovable die from the tubing during upward movement of the punch andfollowing retraction of the punch from the tubing and completingretraction of the movable die ahead of completion of the upward movementof the punch, a horizontally movable plunger carried by the movable diebelow the cavities of the dies and providing a support for the tubingplaced between the dies while the dies are separated, a spring urgingthe plunger toward the fixed die, means for latching the plunger withinthe movable die when the movable die has advanced against the tubingwhereby the formed and pierced tubing may gravitate from the dies whenthe dies are separated, and means for retracting the latching means fromthe plunger during upward movement of the punch following completeretraction of the movable die.

6. Apparatus according to claim 5 having a magazine for holding aquantity of lengths of tubing, and means operated by the reciprocatorymember, while the dies are separated and the plunger is unlatched and ismoved by its spring

